1. Field of the Invention
This invention relates generally to a firing circuit for triggering a detonator and more particularly to a firing circuit for energizing the detonator which triggers the explosive train in a piece of ordnance.
2. Background of the Invention
Involved in the testing of target vulnerability to attack, missiles such as anti-tank missiles are placed on a rocket powered sled and launched toward the target.
Live fire vulnerability tests measure a target's vulnerability to attack and require precise target impacts, far better than that which could be achieved by a missile traveling in air, for example, 3000 meters. Typically, a test bed for conducting live fire vulnerability tests includes a length of track, for example 100 feet or more in length, on which is placed a sled. Rocket motors are placed on the sled and used to propel the sled and missile down the track to impact with the target. Associated with each of the missiles is a device known as a safe and arming (S&A) device which contains a small detonator for firing the warhead.
Warhead penetration is a function of the standoff of the warhead from the target. As this distance decreases, the penetration decreases. A typical missile used in a live fire vulnerability test bed has an 18 inch probe that sticks out in front of the warhead to increase the standoff distance. A detonator that functions in greater than 20 microseconds will defeat the standoff and degrade penetration. Safe detonators such as blasting caps, have been found to be undesirable because they function in 1000 to 10,000 microseconds which defeats the standoff and degrades penetration. If, for instance the missile were traveling on the track at 700 ft/sec. and a blasting cap took one millisecond to function, the standoff would be degraded by 8.40 inches, which is completely unacceptable. Detonators that typically function in less than 20 microseconds have been found to be extremely dangerous since they are highly susceptible to static electricity.
In the past, the detonators were placed on the sled and were oriented 90.degree. out of line with the warhead and subsequently rotated into alignment after the missile is launched toward the target. A high failure rate resulted. A more reliable method of firing the missile resulted when the detonator was placed permanently against the warhead in a special housing; however, this method also proved to be extremely dangerous to personnel working in the immediate vicinity.
Recently a detonator has been found that is relatively safe to handle. It comprises an exploding bridge wire (EBW) detonator, Model RP80 manufactured by Reynolds Industries, Inc. of San Ramone, California. Because of the relatively high energy required to fire this type of detonator, the RB80 EBW needed to be fired with a relatively complicated and expensive firing set.
Accordingly, it is an object of the present invention to provide an improvement in warhead initiation circuits.
It is another object of the invention to provide a relatively simple yet efficient firing circuit for triggering the detonator of a missile warhead.
It is still a further object of the invention to provide a warhead initiation circuit for actuating the detonator of a missile warhead during a target vulnerability test.